If the user has set no title for their blockinstance, show a default [No...

If the user has set no title for their blockinstance, show a default [No title] message when editing the view. This means the blockinstance can still be dragged around.

htdocs/theme/default/templates/view/blocktypecontainerediting.tpl

     <div class="blockinstance" id="blockinstance_{$id}">
         <div class="blockinstance-header">
-            <h4>{$title | escape}</h4>
+            <h4>{$title|default:"[$strnotitle]"|escape}</h4>
         </div>
         <div class="blockinstance-controls">
         {foreach from=$movecontrols item=item}